Adjustable scaffold base



1951 T. c. NORTH ADJUSTABLE SCAFFOLD BASE 5 Sheets-Sheet 1 I Filed Sept.18, 1946 1 INVENTOR.

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T. C. NORTH ADJUSTABLE SCAFFOLD BASE Nov. 20, 1951 3 Sheets-Sheet 2Filed Sept. 18, 1946 l J V INVENTOR.

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1951 T. c. NORTH ADJUSTABLE SCAF'FOLD BASE 3 Sheets-Sheet 3 Filed Sept.18, 1946 INVENTOR. 4M 121M rA/esss 5. BY 25 W1 wrfldwm a r role/vs YsPatented Nov. 20, 1951 UNITED STATES PATENT "OFFICE ADJUSTABLE SCAFFOLDBASE I Thomas C. North, Zelienople, Pa., assignor to Universal Fittings& Scaffolding Company, Zelienople, 2a., a corporation of PennsylvaniaApplication September 18,1946, Serial No. 697,605

ticular, to a scafiold base or substructure for supporting prefabricatedunits of scaffolding.

In many cases the ground or foundation on which a scaffold rests isuneven and, in order to provide horizontal working platforms, thescaffold legs must be adjusted vertically to compensate for theunevenness. Such adjustments have been accomplished in various ways,such as by using telescoping legs or by adding short adapter lengths tothe lower ends of the legs. In either case the scaffold may tend to beunsteady and to wobble if the legs are lengthened very much.

A major disadvantage of prior scaffolds arises when the ground slopesupwardly away from the wall along which the scaffold extends. Thescaffold legs next to the wall can be lengthened or blocked up to levelthe scaffold, but that raises the lowest stage or working platform thatmuch farther from the ground level at the wall. A workman standing onthe ground then no longer may be able to work up to the first platformwithout standing on an improvised support. This is because the endpanels of such scaffolds are of a height that just allows an averageworkman standing on a platform or surface even with the bottom of thepanels to work convenientlyup to the next platform, a distance generallyof about four and a half or five feet.

It is among the objects of this invention to provide a scaffoldsubstructure which makes vertical adjustment of the scaffold legsunnecessary, which is formed to support a working platform at anydesired level above the ground, which has strong and rigid verticallyadjustable legs, and which can be quickly and securely fastened to ascaffold mounted thereon.

In accordance with this invention a scaffold substructure is formed froma pair of spaced, parallel end frames connected together by braces thathold them upright to form a stablestructure. Each of the frames includesa pair of spaced, parallel legs which are connected together below theirupper ends by means of a horizontal cross member which is adapted tosupport the planks of a working platform. The cross members also are.designed for supporting a scaffold. The cross members are connected tothe legs by members, preferably collars, that are adjustable axially ofthe legs so that the cross members can be moved up and down on the legs,or the legs can be adjusted vertically relative to one another tocompensate for uneven ground on which the substructure may rest.

The collar may be provided with transverse 6 Claims. (01. 304-2.)

. openingsa'dapted toregister with different verticallyspacedopenings'in the legs, and pins can the collar-in place. cross' bracesconnect the cross members and inbe inserted in the registering openingsto hold Most suitably, horizontal clined braces connect the legs. Theends of the inclinedbraces may be connected to the legsat any of the legopenings so that when a vertical "adjustment of the legs is-made, theposition of which Fig. 1 is an end 'view of the substructure showing ascaifoldfunit supported thereon; Fig. 2 a side View of the sameassembly; Fig. 3 a plan view of the substructure; and'Figs. 4 and 5enlarged sections along lines IV-IV and VV of "Figs. 1 and 2,respectively.

- Referring to the drawings, the substructure l comp'risesa pair ofspaced, parallel end frames 2 5 and3 each of which has a pair ofvertical legs 4 and-5 connected together by a horizontal cross member 6.The legs preferably are formed from pipe,- and the cross member from anangle bar which is adapted'to support planking (not shown) on its uppersurface inorder to form a stage or working platform. Beneath'the crossmember the legs are connected by an inclined brace l.

Horizontal braces 8, Fig. 3, extend diagonally between the cross membersof the end frames to maintain them-parallel and to help keep themsquare. As'best seenin Fig. 5, braces 8 are con- 'nected to thehorizontal crossmembers by downwardly projecting pins 9 formed on theends of the braces and fitting into vertical sleeves l0fwelded'tothe-inside of the cross members. The

sleeves are positioned on the lower-portions of the cross members sothat when pins 9 are inserted therein the tops of braces 8 will lie in aplaneat least as low as th upper surface'of the crossmembersinorder'toavoid interfering with .the Workin per orm; The endframes also are connected together by .inclined braces i I attached totheir legs. The substructure can be extended to any desired length byadding more end frames and the necessary braces.

Thev substructure, as stated, is designed for I suppoftinga scaffold.One scaffold unit, shown mounted on the substructure Figs. 1 and 2, canbe of anystandard type known to this art. This unit is formed fromspaced apart prefabricated end frames each havingtubular legs [2connected by suitable braces, and braces [3 connecting the endframes toform a rigid structure.

frames for holding them upright, each of said substructure framesincluding a pair of spaced parallel legs independently adjustablevertically relative to each other, a horizontal cross member between thesubstructure legs adapted to support a working platform, meansadjustable axially of the said substructure legs for connecting the endsof said cross members thereto a material distance below the upper endsof the legs, the legs of each end frame of said scaffold resting on thecross member of each end frame of said substructure whereby saidscaifold is supported, vertical plugs projecting upwardly from the endsof each cross member and adapted to project into the legs of saidscaffold, a yoke straddling the upper end of each substructure leg, andmeans pivotally connecting the yoke to that leg to permit the free endof the yoke to be swung to a position above the underlying cross member,said free end of the yoke being bifurcated to adapt it to straddle anadjacent scaffold leg supported by said cross members.

3. A scaffold substructure for use in supporting a scaffold formed of apair of spaced parallel end frames each having a pair of spaced parallellegs, said substructure comprising a pair of spaced parallel end frames,and braces connecting said frames for holding them upright, each of saidsubstructure frames including a pair of spaced parallel legsindependently adjustable vertically relative to each other, a horizontalcross member between the legs adapted to support a working platform,said cross members having a flat upper surface, collars secured to theopposite ends of each cross member and slidably receiving the legs, eachof said legs being provided with vertically spaced openings, saidcollars being provided with transverse openings, means adapted to beinserted in said collar openings and any of said leg openings to lockthe cross members on the substructure at different levels, the legs ofeach end frame of said scaffold resting on the cross member of each endframe of said substructure whereby said scaifold is supported, verticalplugs mounted on said flat surface of each cross member near its ends,said plugs projecting upwardly and being adapted to project into thelegs of said scaffold resting on said flat surface, and clamping meanspivotally connected to the upper end of said substructure legs andadapted to be swung into clamping engagement with an adjacent scaffoldleg supported by said cross members.

4. A scaffold substructure for use in supporting a scaffold formed of apair of spaced parallel end frames each having a pair of spaced parallellegs, said substructure comprising a pair of spaced parallel end frames,and braces connecting said frames for holding them upright, each of saidsubstructure frames including a pair of spaced parallel legsindependently adjustable vertically relative to each other, a horizontalcross member between the legs adapted to support a working platform,means adjustable axially of said substructure legs for connecting theadjacent ends of said cross members thereto, the legs of each end frameof said scafiold resting on the cross member of each end frame of saidsubstructure whereby said scaffold is supported, means between said pairof legs projecting upwardly from each cross member and adapted toreceive the feet of the scaffold and keep them from moving laterally,clamping means connected to said frame and adapted to grip the legs ofsaid scaffold. and hold the scaffold on said cross members.

5. The combination of a scaffold and a scaffold substructure, saidscaffold comprising a pair of spaced parallel end frames and bracesconnecting said frames for holding them upright, each of said end framesincluding a pair of spaced parallel legs and a cross member between thelegs; and said substructure comprising a pair of spaced parallel endframes, and braces connecting said frames for holding them upright, eachof said substructure end frames including a pair of spaced parallel legsindependently adjustable vertically relative to each other, a horizontalcross member between the legs adapted to support a working platform,means adjustable axially of said legs for connecting the ends of saidcross member thereto, the legs of each end frame of said scaffoldresting on the cross member of each end frame of said substructurewhereby said scaffold is supported, and means mounted on each of saidsubstructure cross members for receiving said scaffold legs and keepingthem from moving laterally.

6. The combination of a scaffold and a scaffold substructure, saidscaffold comprising a pair of spaced parallel end frames and bracesconnecting said frames for holding them upright, each 3, of said endframes including a pair of spaced parallel legs and a cross memberbetween the legs; and said substructure comprising a pair of spacedparallel end frames, and braces connecting said frames for holding themupright, each of said substructure end frames including a pair of spacedparallel legs independently adjustable vertically relative to eachother, a horizontal cross member between the legs adapted to support aworking platform, means adjustable axially of said legs for connectingthe ends of said cross members thereto a material distance below theupper ends of the legs, the legs of each end frame of said scaffoldresting on the cross member of each end frame of said substructureWhereby said scaffold is supported, means between said pair of legsprojecting upwardly from said substructure cross members for receivingsaid scaffold legs and keeping them from moving laterally, and clampingmeans pivotally connected to the upper end portions of the substructurelegs for gripping the scaffold legs and holding the scaffold on saidsubstructure end frames.

THOMAS C. NORTH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 787,233 Tingleaf Apr. 11, 19051,552,333 Mosher Sept, 1, 1925 1,880,767 Burt Oct. 4, 1932 2,126,844Uecker et a1. Aug. 16, 1938 2,361,614 Dungan et a1 Oct. 31, 1944 FOREIGNPATENTS Number Country Date 15,346 Great Britain Dec. 21, 1914 452,286Great Britain Aug. 20, 1936 657,686 Germany Feb. 24, 1938

